Table of Contents
Diseases of animals remain a principle concern because of the economic losses they cause and the possible transmission of the causative agents to humans. The branch of medicine called veterinary medicine deals with the study, prevention, and treatment of diseases not only in domesticated animals but also in wild animals and in animals used in scientific research. The prevention, control, and eradication of diseases of economically important animals are agricultural concerns.
A disease to which animals are liable and whereby the normal functions of any organ or the body of an animal is impaired or disturbed by any protozoon, bacterium, virus, fungus, parasite, other organism or agent
Types Of Animal Disease
Diseases may be either infectious or noninfectious.
Anhrax, a highly infectious and fatal disease of cattle, is caused by a relatively large spore-forming rectangular shaped bacterium called Bacillus anthracis. Anthrax causes acute mortality in ruminants.
Black quarter (black-leg)
It is an acute infectious and highly fatal, bacterial disease of cattle. Buffaloes, sheep and goats are also affected. It is soil-borne infection which generally occurs during rainy season. In India, the disease is sporadic (1-2 animal) in nature.
Foot and mouth disease
The foot-and-mouth disease is a highly communicable disease affecting cloven-footed animals. It is characterized by fever, formation of vesicles and blisters in the mouth, udder, teats and on the skin between the toes and above the hoofs. Animals recovered from the disease present a characteristically rough coat and deformation of the hoof.
Rabies (Mad dog disease)
Rabies is a disease of dogs, foxes, wolves, hyaenas and in some places, it is a disease of bats which feed on blood.
The disease is passed to other animals or to people if they are bitten by an animal with rabies. The germs which cause rabies live in the saliva of the sick (rabid) animal. This is a killer disease but not every dog which bites is infected with rabies.
Bluetongue, a disease which is transmitted by midges, infects domestic and wild ruminants and also camelids, however sheep are particularly badly affected. Virus spreads between animals occurs via the midges of Cullicoides species.
Sheep-pox is a highly contagious disease. It causes a mortality of 20 to 50 per cent in animals below the age of 6 months, and causes damage to the wool and skin in adults.
This is an infectious, non-febrile disease of animals and man, and is characterized by spasmodic tetany and hyperaesthesia. This disease is prevalent all over the world.
This disease occurs by coitus. The affected bulls carry the organisms in preputial cavity indefinitely. Infected semen from an infected bull is the important means of the disease. The organism survives low temperature used in semen storage.
It is a specific chronic contagious enteritis of cattle, sheep, goat, buffaloes and occasionally of pigs. The disease is characterized by progressive emaciation and in cattle and buffaloes by chronic diarrhea and thickening of the intestine.
Bovine Ephemeral Fever
It is an insect-transmitted, noncontagious, viral disease of cattle and water buffalo that is seen in Africa, the middle east, Australia, and Asia.
The most common lesions include polyserositis affecting pleural, pericardial, and peritoneal surfaces; serofibrinous polysynovitis, polyarthritis, polytendinitis, and cellulitis; and focal necrosis of skeletal muscles.
Infectious bovine rhinotracheitis (ibr) is a highly contagious, infectious respiratory disease that is caused by bovine herpesvirus-1 (bhv-1). It can affect young and older cattle. In addition to causing respiratory disease, this virus can cause conjunctivitis, abortions, encephalitis, and generalised systemic infections.
This is the most common infectious skin disease affecting beef cattle. It is caused by a fungus, and is transmissible to man. Typically, the disease appears as crusty grey patches usually in the region of the head and neck and particularly around the eyes.
It is also known as Parturient hypocalcaemia and parturient paresis, is a disease which has assumed considerable importance with the development of heavy milking cows. The basic cause of this disease is decrease in the levels of ionized calcium in tissue fluids. It usually occurs in 5 to 10-year-old cows, and is mainly caused by a sudden decrease in blood-calcium level, generally within 48 hours after calving.
Calves may develop scours due to bacterial or virus infections. Scours is known as “calf scours” or neonatal calf diarrhea.
Animal Disease – Facts
- It is estimated that every year one of five animals in a farm are lost due to disease.
- Animal health products help protect, diagnose and treat animals against disease.
- As the disease are in a state of constant, new and innovative medicines will be needed to counter each new threat to animal wellbeing.
- . As encouraging more vaccination and preventative treatments, we should be more attentive against new and emerging diseases.
- Disease control and elimination programs require many sophisticated techniques in addition to diagnosis and the slaughter of affected animals.
Animal Disease – Diagnosis
Before treating an unhealthy animal an attempt should be made to diagnose the disease. A clinical examination of animal is necessary to establish the cause of disease. It is necessary to check if the animal is in good physical condition, is eating adequately, is bright and alert, and is functioning in an apparently normal manner. Many disease processes are either inflammatory or result from tumours. Malignant tumours tend to spread rapidly and usually cause death. Other diseases cause the circulatory disturbances or the degenerative and infiltrative changes.
The veterinarian must diagnose a disease on the basis of a variety of examinations and tests, since veterinarian obviously cannot interrogate the animal. Methods used in the preparation of a diagnosis include
Inspection—a visual examination of the animal;
Palpation—the application of firm pressure with the fingers to tissues to determine characteristics such as abnormal shapes and possible tumours, the presence of pain, and tissue consistency;
Percussion—the application of a short, sharp blow to a tissue to provoke an audible response from body parts directly beneath;
Auscultation—the act of listening to sounds that are produced by the body during the performance of functions (e.g., breathing, intestinal movements);
Smells—the recognition of characteristic odours associated with certain diseases;
and miscellaneous diagnostic procedures, that includes eye examinations, the collection of urine, and heart, esophageal, and stomach studies.
The types of diagnosis for animal disease includes:
- The appearance of an animal – Small size in a pig may result from retardation of growth, which is caused by hog-cholera virus.
- The behaviour of an animal – Examining neurological disease
- The general condition of the body – Examining diseases that cause excessive leanness (emaciation), including certain cancers, or other chronic diseases, such as a deficiency in the output of the adrenal glands or tuberculosis.
- The respiratory movements of an animal – Breathing is rapid in young animals, in small animals, and in animals whose body temperature is higher than normal. Specific respiratory movements are characteristic of certain diseases or the abdominal breathing of animals suffering from painful lung diseases.
- The appearance of the skin and hair – Indicate dehydration by lack of pliability and lustre; or the presence of parasites such as lice, mites, or fleas; or the presence of ringworm infections and allergic reactions by the skin changes they cause.
- Abnormal activities – Straining during urination is associated with bladder stones; increased frequency of urination is associated with kidney disease (nephritis), bladder infections and a disease of the pituitary gland.
Following the general diagnosis a thorough clinical examination is necessary for treating animals in which various features of animals are studied. These include the visible mucous membranes (conjunctiva of the eye, nasal mucosa, inside surface of the mouth, and tongue); the eye itself; and such body surfaces as the ears, horns (if present), and limbs. In addition, the pulse rate and the temperature are measured.
To determine if jaundice, hemorrhages, or anemia are present in the animal body, the veterinarian examines the visible mucous membranes of the eye, nose, and mouth. Ulceration of the tongue may be detectable in animals suffering from actinobacillosis, a disease of bacterial origin.